Numerous cellular processes are regulated by reversible protein phosphorylation with approximately 30% of proteins being phosphorylated during their lifespan Crude cell extracts contain various endogenous enzymes such as phosphatases and proteases which can degrade and alter proteins in the extracts Therefore the optimal method to increase the yield of intact proteins is to add inhibitors targeting these enzymes Phosphatase Inhibitor Cocktail 3 inhibits alkaline phosphatase L-isozymes and serine/threonine protein phosphatases such as protein phosphatase 1 and 2A (PP1 and PP2A) Phosphatase Inhibitor Cocktail 3 has been optimized and tested in cell extracts from various animal tissues Phosphatase Inhibitor Cocktail 3 can replace Phosphatase Inhibitor Cocktail 1 as the two cocktails have equivalent activities Phosphatase Inhibitor Cocktail 3 contains Cantharidin Bromotetramisole and Calyculin A This Phosphatase Inhibitor Cocktail is supplied as a ready-to-use solution in DMSO